Spark recording system



March 31, 1936. D. 1 HAY 2,035,474

SPARK RECORDING SYSTEM Filed Feb. 2l, 1955 c /A/VE/VTOR Donald Hc?? BY W lam-4MM?.-

ATTORNEY Imalsaine,wnniilmam, no.. Anneau.- nsmry si, im. sain n. man

(Cl. :S4-1.5)

(Granted under the act of March s, ma, u'

.mended April $0, 19u; 310 0. G. 751) This invention relates to improvements in apparatus for spark recording and particularly to a system whereby the record is made in color. In the usual method of spark recording, the spark s merely perforates the recording paper or at most slightly burns it when a strong spark is used. In the method employed by the apparatus herein described each perforation is surrounded by a small ring of color which makes it distinctly visible. The color may be varied at will so that in the eventseveral records are made on the same chart, they may be recorded in diiferent colors, making them readily distinguishable.

An object of this invention is to provide a simpie, convenient color recording system suitable for use in any type of recording apparatus wherein a permanent record in one or more colors is desired.

Another object is to provide an apparatus for color electric recording in which the time of occurrence of recorded events and the polarity of electric signal impulses corresponding thereto may be determined from the record.

A still further object of the invention is to provide an apparatus for electrically recording several records upon a single recording strip in such a manner that the superposed records may each be examined independently by the various difier- A ent colored records. Referring now to the drawing forming a pari of this specification:

Fig. 1 is a schematic showing of the spark recording arrangement;

Figs. 2 and 3 are sectional views of the sparking electrodes and perforated sheet;

l Fig. 4 is a sectional view of another form wherein the polarity of the current producing a spark may be determined by the record made:

Fig. 5 shows schematically an apparatus for making spark records in several colors.

Referring to Fig. 1, a flat electrode is shown at 2 on which is placed a sheet of paper 3 above which and in close proximity thereto is a pointed electrode I. Electrodes I and 2 are connected by suitable wires to the secondary winding 4 of a spark coil whose primary winding I is connected in circuit with a battery 8 and switch 1. The electrode I may be of any suitable electrically'conducting material such as copper, iron or platinum. The electrode 2 is a conducting plate into which a dye of a desired color has been incorporated. A nely porous carbon plate saturated with dye has been found to be very good. For some purposes, however, an electrode made of wax with the dye 56 dissolved in it and graphite carbon powder or powdered metal added to give sumcient electrical conductivity has been used. Upon opening the switch 1, a spark passes between electrodes I and 2 perforating the paper and leaving a colored spot around it the color of which is determined by the dye carried by the electrode 2.

A large variety of dyes may be used. It is preterable. but not absolutely necessary, to use dyes which will vaporize without decomposing. The dyes used determine to some extent theymaterial lo used for the electrode. For example, with a great many dyes powdered zinc cannot be used to give conductivity to a wax electrode since under the action oi' the spark the metal reacts with the dyestun' and destroys the color. In general, carbon 15 or graphite is non-reactive and very satisfactory.

As examples ofthe dyes which may be used to produce different colors, the following may be cited:

Red Sudan IV, Oil Soluble Red, ctc. 2o Orange Oil Soluble Orange Yellow Butter Yellow, Oil Soluble Yellow Green Malachite Green, Oil Soluble Green Blue -Oil Soluble Blue 25 It is also possible to produce a number of colors by the use of pure metals, semi-metals or alloys for the electrodes instead of dye bearing In like manner, a great many colored inorganic 40 compounds may be used. It is not even necessary that the materials used be colored. The electrode may be impregnated with a mixture oi.' two or more chemical substances which under the action of the electric spark interact to form 45 a colored compound which is deposited on the paper. On the other hand, one chemical may be incorporated in the electrode and the other in the paper, the interaction of the two produc- 'ing a colored deposit. 5

The kind of paper used is more or less immaterial, and, with the exception of the cases just cited, requires no chemical treatment before or after use. u

The size of the colored spot around the perforations is determined by the material used for the electrode and the intensity of the electric spark. In general it is best to use as weak a spark as possible consistent with reliable operation, as this eliminates any `burning of the paper and enhances the brilliance of the colors..

The eiect obtained also depends upon the polarity of the voltage applied to the electrode.

When the electrode containing the coloring ma;-`

terial is made negative, the color is deposited in a ring around perforation 8 on the side nearest this electrode as shown at 9 in Fig. 2. With this electrode made positive. very little color carried onto the paper and this is deposited in the interior of the hole 8 as shown in Fig. 3 in which case both sides of the paper are only slightly colored.

This also applies to metallic electrodes. By utilizing this polarity effect, it is possible to make a record of the time and polarity of a spark signai as follows: The paper.3, Fig. 4, is moved along over the electrodes 2 and 2' in a direction perpendicular to the plane of the figure. Electrodes 2 and 2' are impregnated with dyes to give different colored spots, for instance, red and green respectively. The point electrodes I and I are placed directly above the electrodes 2 and 2' and in'close proximity to paper 3. 1f a spark is allowed to pass between the electrodes with l the positive and I' the negative, a bright red spot is produced on the under side of the moving paper 3 under electrode I while only a very faint green spot equally visible on both sides of the paper is produced under I'. With the electrode I' made positive and I negative, a bright green-spot is produced on the under side of the paper under I' and a faint red spot equally visible on both sides of the paper under I. The position of the spots on the paper indicates the time of occurrence of the spark when paper 3 is moved at a uniform rate and the color of the spot indicates the polarity of the spark.

In another form ofthe spark recorder a paper strip 3 (Fig. 5) moves in the direction of its length at a uniform speed. Directly above the paper is a point electrode I which is arranged to be movable along the line perpendicular to the direction of motion of the paper. Immediately below the paper and in contact with it is a narrow extended electrode fixed so as to be directly under the path of the movable point electrode. When the spark takes place, a perforation is made in the paper at the position occupied by the point electrode at the instant the spark takes place. If the spark is caused to take place at regular intervals, a more or less continnous record of the position of the point is serecorded simultaneously on the same chart by alternately making the position of the spark point at the time the spark occurs correspond iirst to ,l

, the perforations are identical, there is no means distinguishing` between thetwo curves. By applying the colored-record scheme and making the extended electrode 2 in the form of a cylinder with a number of strips of dye-bearing electrode 2a, 2b, 2c, etc., each spot may be made in any desired color by rotating the proper colored electrode under the electrode I at the instant the spark occurs. In this way a number of records may be taken by the same movable electrode 'I on the same chart 3 in diil'erent colors and there is no possibility of confusing the dierent curves even though they cross each other. The above description has` dealt with a relatively. at or slightly curved electrode 2, although I do not intend to limit myself to this particular form. It is quite feasible to vary the shape of the electrode 2, or to make the point electrode of a color-producing metal or porous conductor impregnated with a dye.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalty thereon.

I claim:

1. In combination, a pair of interconnected dye-bearing electrodes, each of said dye-bearing electrodes containing a dye of a distinctive color different from the other; a pair of pointed electrodes disposed one adjacent to one of said dyebearing electrodes and one adjacent the other, a record sheet interposed between said interconnected dye-bearing electrodes and said pointed electrodes, and means for producing a high potential spark discharge of selected polarity between the pointed electrodes and the dye-bearing electrodes whereby the polarity of the potential causing said discharge may be determined by the color of the dye most abundantly deposited on the surface of the record sheet carried by the said dye-bearing electrodes and said pointed electrodes.

2. A spark recording device, comprising an electrode composed of a nely divided conducting material and a dye, a second electrode adjacent thereto and means for applying a high potential between said electrodes whereby a spark is produced for periorating and coloring a record sheet therebetween.

3. An electrode for spark recording in color, comprising a finely divided electrical conducting material, a coloring material and abinder.

4. An electrode for spark recording in color, comprising a nely divided metallic substance, a coloring material and a binder.

DONALD L. HAY. 

